This invention relates to apparatus for medical photography and more particularly to a method for obtaining an intense beam of light in a concentrated area for use in the medical photography field.
Medical photographs are widely employed and used in teaching as well as for the presentation of various data to other practitioners. A great many such photographs are taken in the operating room by a surgeon during the course of an operation. Such photographs are made by employing conventional photographic techniques utilizing a camera with flash bulbs, flash guns and so on.
Most available flash guns as well as electronic flashes employ the well known Fresnel lens or another type of deflector which essentially operates to spread the flash or beam over a wide area. The basic concept in photography is to illuminate as much an area as possible by means of a flash or a flash gun in order to obtain a wide field of view to enable one to take a picture of a large area. Such techniques as using conventional flash bulbs and flash guns has resulted in problems in the field of medical photography. In medical photography the color red and the fidelity of portraying the color red is a substantial problem.
As is known, red is the color of blood, various vessels as well as a predominate color of the organs and other internal body parts. Hence it is a basic objective in the field of medical photography to present the color red and its various hues as true as possible. The response of various films to the color red varies greatly. For example, slower films have a much better response to the color red then higher speed films. A very popular type of film is sold under the trademark Kodachrome by the Kodak Company of Rochester, N.Y. This type of film is a relatively slow film but has an excellent response to the color red. A higher speed film which is a more sensitive film is sold under the trademark Ektachrome by the same manufacturer.
This film, while faster, has a poorer response regarding the fidelity of the color red. Ektachrome is widely employed due to the fact that the amount of light required to expose the film in the given time period is much less than that required for Kodachrome.
A further problem is compounded by the fact that conventional light or flash attachments for cameras operate to disperse the beam over a wide area and hence require the use of a high speed film due to the spreading of the beam from the flash bulb or flash gun. Hence it is an object of the present invention to obtain an intense beam of light from a conventional flash which beam is directed in a concentrated area and employed for medical photography.
The concept of this invention allows one to obtain a greater depth of focus with a higher f-stop on a camera and thereby enables one to utilize a slower film which has a greater response to the color red.